Hi I think you are correct as the popping is caused by unburnt fuel exploding after the cat and in the exhaust which is basically untreated hydrocarbons and C02, the side benefit of this is that if you still have a cat it will destroy it, some people even have spark plugs fitted past the silencer which ignites the unburnt fuel so you have popping and flames emanating from the exhaust, when I used to work nights any driver going to anywhere near Lakeside retail park lived in fear of the hoards of lunatics popping and flaming as they forced you in to the middle of the dual carriageways whilst overtaking both sides of your vehicle, the Police claim to have not enough officers to cover the area and no powers to stop this, well, they will have soon, some Thurrock drivers can attest to horrific accidents a lot of them high speed and caused by defects in braking and suspension, why not forget the overpriced straight through exhaust and its remap and spend the money on making sure you can stop and go around corners, my main objection is when they take some unsuspecting soul out as well, why does insurance cost so much because you can bet your bottom dollar that alarge percentage of these people with modified cars don't declare the said modification because they won't get insurance therefore what they do have insurance wise is void via the non disclosure clause on their policy, this leaves any victims of their stupidity with what? you got it, claiming off their own insurance. Steve.